Rotary core drill



Patentes May e, 1924.

JOHN' E. ELLIOTT, 0F L OS ANGELES,

QALIFORNIA.

ROTARY com; DRILL.

appncanon mea my 1s, 1922. semina. 560,760.

To all 'whom t may concer/n.'

Be it known that I, JOHN E. Enuo'rr, a citizen of the United States`residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented a new and usefulv Rotary Core Drill, of whichthe following is a specification.

This invention relates to -an improved rotary core drill, particularlyof the type by which a sample core is formed and extracted to determinethe character of formation encountered.

An object of the invention is to provide a core drill in whichn the coreis protected against flushing action of the circulating water and thecuttings of the core bit are directed into the path of the circulatingWater;

Another object is to provide a core drill in which thecore will notbecome jammed or froze 'in the core barrel, and in which the core issubjected to a minimum amount of friction so as to prevent a burning ofthe core. y

A. further object is to provide a core drill bits, and in which thecuttings of the core bit are directed in the path of the outer boringbits and the outer borin bits formed to urge the cuttings towards teouter pei ri her of the drill.

arlous other objectsand advanta es will be more fully aplparent from thefoI lowing description of t e accompanying drawings which form a part ofthis disclosure, and which illustrate a preferred form of embodiment ofthe invention.

' Of the drawings:

Figure 1 is a vertical section through my improved core drill. l

Fig. 2 is a bottom plan view of the cutter head removed from the body.

Fig. 3 is an elevation thereof.

Fig 4 is a detail view illustrating the manner in which the cuttings areremoved.

Fi 5 is a detail view showing a modified orm of cutter head.

In drilling wells, particularly oil wells, it is often desirable toobtain sa les of the formation through which the drllling tool A ispassing for the purpose of determining the presence or absence of oil orother minerals and for obtaining a record of the various strataencountered, and in providing a core drill for this purpose which willsuccessfully function in the various types of having a central core bitand outer boring up of several sections formation certain requirementsmust be rigidly adhered' to. As a drill of this charf acter isordinarily operated in the presence of circulating flushing water whichcarries the cuttings to the surface, it will be understood that thecore, especially when o erat lng 1n soft or sand formations, must e ef``fectively protected against the {iushing action of the water. Thisprotection is best afforded by providing a central tubular core bitwhich extends beyond the outer boring bits and by so extending said corebit is becomes necessary to provide'for an effective means for freelydisposing of the cuttings of the core bit so its cutting action will notbe hampered.

A. further important requirement in a core drill resides in'providingrelief for the core immediately after it' is formed or as soon tworeasons for this requirement; one of Vwhich is based upon the fact thatin deep considerable load pressure, a ccore as soon as formed has atendency to expand rather y 1,493,112 PATENT l oFFlcE..

475 after it is formed as is practical. There are i -than shrink .withthe result that the-core has I a snug fit in the core bit and in thecore receiving barrel -wheresuch .barrel is of the same' internaldiameter as the core bit. This, during the continued rotation 'of thedrill relative to the stationary core will create sufficient friction tocause a burning of the core and destroy its usefulness 'as an l accuratesample' of the formation and its contents. In addition to this, suchfrictional heat will expandl the core and cause it .to clo or becomefroze in the bafrrel. nother reason for providing such relief is for theurpose of retaining the core within the dri l, it being evident thatafter expanding in not again pass downwardly through the smaller corebit.

an enlarged core barrel it can- The core'drill of the `present inventionfulfils each of the above 'requirements in the ellicient and. racticalmanner explalned in connection with the following detailed descriptionof the preferred form of embodiment illustrated 1n the drawings.

With particular reference to Fig.. 1, the

drill comprises a body 1 screw threaded .on the lower end of a tubularshank 2, which may be of any desired length and following the usualpractice may be considered as made of drill pipe,

joint 3 being joined to the top of the shank a tooll i roughenedsurface,

of a plurality of upwardly directedteeth 2 for connection with a stringof drill tubin in the usual manner.'

he body 1 has a central core receiving bore 4 and joined to the body' inalignment -with the bore 4 is a core barrel 5 extending upwardly intoand spaced from the walls of' the tubularshank 2. A check valve 6carried by the upper end of the core barrel 5 permits water 'in saidbarrel to be expelled into the shank as the. core moves into the lbarrelbut prevents the flushing water /entering the upper end of the barrel.

A toolhead 7 is secured to the bottom end of the body 1. by bolts 8 orby any other suitable means and in general terms said tool headcomprises a central tubular' toothed core bit 9 havingits bore alignedwith and of a lesser. diameter than the bore 4 of the body, and aplurality of outer cutters 10 surrounding the core bit 9.

rlhe upper portion of the bore of the core bit 9 tapers to the largerdiameter of the \bore 4 and is provided with a serrated or preferably inthe form or toothed tapered sur- 11, such roughened means of retainingthe faces serving as a core within the tool. v

As shown in the drawings, the teeth 12 of the core bit 9 extend beyondthe cutters 10 and the bit between adjacent teeth 'is chamfered upwardly13 to provide a means for directing the cuttings from the teeth 12upwardly and outwardly into the path of the outer cutters 10.

The cutters 10 have their cutting edges 14 Y angled outwardly andbackwardly relative to the direction of rotation of the drill so as tourge the cuttings towards the outer periphery of the drill, 'each cutterand each of the teeth 12 of the core bit 9 being provided with properrelief rearwardly of their cutting edges to produce an eiicient cuttingaction. i v

The body 1 and tool head 7 are providedI with aligned ports 15-16, whichcommuni` cate with 'the space between the core barrel '5 and theltubular shank 2 and direct the flushing water to the cuttinv edges ofthe outer cutterslO where it wil pick up and carry the cuttings insuspension upwardly between the tool and the wall of the well In Fig. 4,I have illustrated in a diagrammatic way, the operation of my improvedcore drill, and in such figure arrows 17 indicate the path' of thecuttings from the core cutting teeth 12 as they are forced upwardly andoutwardly into the path of the outer cutters 10, and arrows 18 indicatelthe path of the fiushingwater andthe cuttings carriedy upwardlythereby, it being noted that the ports do not' direct the water directlagainst, the core bit 9 in a manner whic might and outwardly as at withcircular teeth aect the core, but the water is' accanita While the formot drill herein illustrated an(l"clesc1il)ed is well adapted to fulfillthe objects primarily stated, it is to be understood that the inventionis not to be limited in this regard, tor it is susceptible ot'ombodiment in various other forms all coming within the scope of thefollowing claims:

1. In a core drill, a body having a tubular shank and a core receivingbore, a core barrel aligned with said boreand extending upwardly fromthe body within the shank, a central tubular core bit aligned with andof lesser internal diameter than the bore, the upper portion of theinner wall of the bit being beveled from its smaller diameter to thelarger diameter of the bore and roughened to frictionally grip a core,and a plulIality of outer cutters surrounding the core shank and a corereceiving bore, a core barrel aligned with said bore and extendingupwardly from the body within the shank, a central tubular core bitaligned with and of lesser internal diameter than the bore, the upperportion of the inner wall being beveled from its smaller diameter to thelarger diameter of the bore and provided l for retaining a core, and aplurality of outer cutters surrounding the core bit.

3. In a core drill, a body having a tubular shank and a core receivingbore, a core barrel ali ed with said bore and extending .upwar ly fromthe body within the shank, a plurality of outer cutters carried" by thebody, and a central tubular core with the bore and -provided withcutting teeth extended below the outer cutters, the corebitbeingchamfered upwardly and outwardl between the cutting teeth with said chamers extending above the lower edge of bit aligned 2. In a core drill, abody having a tubular l of the bit Wardly from the body Within theshank` a plurality of'. outer cutters carried by the body, and a centraltubular core bit aligned with the bore and provided with cuttin teethextended vbelow the buter cutters and chamfered to directcuttingsupwardly and outwardly into the ath of the outer cutters. 5. A cutterhea Afor rotary coredrills, comprising a plurality of circula-rlydisposed u outer cutters, and a central tubular core bit provided withcuttingJ teeth at yits lower end, the teeth projecting elow the outercutters and the bit between the teeth being chamfered outwardly andupwardly beyond the lower edges of the outer cutters to direct cuttingsinto the path of the outer cutters.

6. In a core drill adaptedy for use on the lower end of aA rotatingshaft, tubular mem- `bers providing a core receiving chamber having thelower end thereof of reduced diameter for a relatively short distance,and

flared upwardly and outwardly to substan- 7. In a core drill adapted foruse on the lower end of a rotating shaft, tubular members providing acore receiving chamber having the lower end thereof of lreduced diametervfor `a relatively short distance and 20 flared upwardly and outwardlyto substantially the diameter above said reduced portion, the flaredportion of-said core receiving chamber being equipped with circularteeth to form a gripping means to prevent the dropping of a core fromsaid chamber, and cutters for forming a core.

Signed at Los Angeles, Calif., this 1st day of May, 1922.

, JOHN E. ELLIOTT.l

Witnesses:

CLARENCE B. FOSTER, L. BELLE WEAVER.

